Flexibility is muscle length. Mobility is tendon length. We commonly understand flexibility a little better, it’s the stretches we’ve been taught since P.E. The concept is lengthening the muscles through extension. But mobility is a little less commonly understood, probably because as a child our mobility is great and so we don’t do much mobility work while growing up. The core property that allows for greater mobility is length in the tendons and the viscoelastic property of becoming either rigid and elastic.
So as we get older how do we improve or regain our mobility? If you think of muscles lengthening through extensions, i.e. straight legs to stretch out your hamstrings. Think of lengthening tendons through flexion. The tendon wraps around the joint, it’s that hinge where the tendon needs to have more length. The tendon will always have enough to work in the mid-range motions but it’s in the deep flexion where the tendon will start to lose its range. But even as we get older, that mid-range can become smaller and smaller, if you’ve ever seen an older person with very short strides walking, the tendons in their ankles, knees and hips have drastically shortened over time. If our body doesn’t get into those deep ranges, our body will deprogram the tendons physical requirements to maintain that ability.
Tendons have amazingly high tensile strength. The achilles tendon can withstand loads of 8x your body weight. They’re like steel cables. Imagine trying to lengthen steel cables. So when we get into a squat and our hips or knees can’t get into a deep crease or try to get deeper dorsiflexion. We seem stuck and hardly able to increase the range because our tendons are so rigid and shortened. So what are the keys to improving mobility.
- Relaxed flexion. Increasing relaxed flexion is the key principle to unlocking mobility. The tendons wrap the hinge of our joints. Imagine a garden hose wrapping around a corner, the garden hose needs more length to be able to comfortably go around the corner. And our joints should be able to crease like a book not fold like a pencil is stuck in the spine. Look at any joint in our body if we cannot get a tight crease in any of our ankle, knees, hips, arms the tendon wrapping that joint is too short to allow that hinge to fold without limiting restriction or impingement.
- Frequency. Do them everyday like eating a meal. You are telling your body that it still needs these body positions. Programming your body to maintain proper nutrition, fluid, circulation, neurological motor, tissue health and repair to those body parts.
- Relax all tension. Relaxing all tension is the only way to reach the end range of your tendon. If there is any bit of tension, the tendon will never lengthen past its current fixed end point.
- Your body weight can only do so much. Once you can get into a deep floor squat and sit comfortably for 2+ minutes. You’ve reached the end of that progression. Your body weight will only do so much to lengthen your tendons. Your tendons will not lengthen past what your bodyweight is producing. Start holding a 5 pound weight in the relaxed flexion. And only start with small incremental weight increases. Using too heavy of a weight will force your body to tense up and contract, remembering the previous rule – relax all tension.